The present technology is generally directed to medical implants, such as stimulation assemblies for stimulating the septal wall of the heart of a human patent, and associated methods. In some embodiments, a stimulation assembly includes a body, circuitry positioned at least partially within the body, an electrode, and an anchor coupled to the body. The anchor can be secured to the septal wall such that the body is positioned within the left ventricle of the heart and the electrode engages tissue of the septal wall. The circuitry can be configured to receive acoustic energy and to convert the acoustic energy to electrical energy, and the electrode can deliver the electrical energy to the tissue of the septal wall to stimulate the tissue.
The present technology generally includes devices, systems, and methods for providing electrical stimulation to the left ventricle of a human heart in a patient suffering from Left Bundle Branch Block (LBBB). In particular, the present technology includes an implantable receiver-stimulator and an implantable controller-transmitter for leadless electrical stimulation of the heart. The receiver-stimulator can include one or more sensors capable of detecting the electrical conduction of the heart and the receiver-stimulator can be configured to pace the stimulation of the left ventricle based off the sensed electrical conduction to achieve synchronization of the left and right ventricles.
Systems, devices, and methods for tracking and determining the motion of a cardiac implant is disclosed. The motion of the implant is determined by transmitting acoustic energy to a tissue location using an acoustic controller-transmitter comprising an array of acoustic transducers; wherein the implant is configured to convert the transmitted acoustic energy to electrical energy; and the tracking is achieved by determining the electrical energy delivered to the tissue throughout one or more cardiac cycles in order to create a motion profile of the cardiac implant.
The present technology is generally directed to delivery systems for medical implants, such as stimulation assemblies for stimulating tissue of a human patent, and associated methods. In some embodiments, a delivery system includes (i) an elongate sheath having a distal portion with a distal opening, (ii) an attachment mechanism positioned within the elongate sheath and configured to be releasably coupled to an electrical stimulation implant, and (iii) an elongate optical component movably positioned within the elongate sheath. The optical component is configured to capture image data, and is movable from a first configuration to a second configuration. In the first configuration, the optical component is positioned proximally of the implant. In the second configuration, the optical component is positioned at least partially adjacent to the implant to capture image data proximate the distal opening, thereby facilitating direct visualization of a target location for implantation of the implant.
A controller-transmitter transmits acoustic energy through the body to an implanted acoustic receiver-stimulator. The receiver-stimulator converts the acoustic energy into electrical energy and delivers the electrical energy to tissue using an electrode assembly. The receiver-stimulator limits the output voltage delivered to the tissue to a predetermined maximum output voltage. In the presence of interfering acoustic energy sources output voltages are thereby limited prior to being delivered to the tissue.
A61N 1/372 - Arrangements in connection with the implantation of stimulators
H02N 2/18 - Electric machines in general using piezoelectric effect, electrostriction or magnetostriction producing electrical output from mechanical input, e.g. generators
H10N 30/03 - Assembling devices that include piezoelectric or electrostrictive parts
H10N 30/30 - Piezoelectric or electrostrictive devices with mechanical input and electrical output, e.g. functioning as generators or sensors
The present technology is generally directed to implantable medical device systems configured to provide cardiac resynchronization therapy. In some embodiments, the implantable medical device system comprises a housing, electrodes carried by the housing, a transducer configured to produce input voltage signals in response to ultrasound energy, and a circuit configured to provide, via an electrical pathway, output voltage signals based on the input voltage signals. The circuit comprises a movable switch, and a slew rate detector configured to detect whether a voltage rate of an individual pulse of the input voltage signals exceeds a predetermined threshold voltage rate. The circuit is configured to move the switch to an open position in response to the detected voltage rate exceeding the predetermined threshold voltage rate.
H02M 3/07 - Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using resistors or capacitors, e.g. potential divider using capacitors charged and discharged alternately by semiconductor devices with control electrode
H02N 2/18 - Electric machines in general using piezoelectric effect, electrostriction or magnetostriction producing electrical output from mechanical input, e.g. generators
7.
TISSUE STIMULATION SYSTEMS AND METHODS, SUCH AS FOR PACING CARDIAC TISSUE
The present technology is generally directed to implantable medical device systems for stimulating tissue, such as heart tissue. In some embodiments, an implantable medical device system includes a controller-transmitter and a receiver-stimulator in operable communication with one another. The receiver-stimulator can be implanted at the heart of a patient. The controller-transmitter can be configured to transmit an acoustic signal to the receiver-stimulator, which receives the acoustic signal and converts the acoustic signal to electrical energy for delivery to the heart via one or more stimulation electrodes. The receiver-stimulator can further be configured to transmit a radiofrequency signal to the controller-transmitter including information about sensed physiological parameters of the patient, status information, and the like.
The present technology is generally directed to implantable medical device systems for stimulating tissue, such as heart tissue. In some embodiments, an implantable medical device system includes a controller-transmitter and a receiver-stimulator in operable communication with one another. The receiver-stimulator can be implanted at the heart of a patient. The controller-transmitter can be configured to transmit an acoustic signal to the receiver-stimulator, which receives the acoustic signal and converts the acoustic signal to electrical energy for delivery to the heart via one or more stimulation electrodes. The receiver-stimulator can further be configured to transmit a radiofrequency signal to the controller-transmitter including information about sensed physiological parameters of the patient, status information, and the like.
The present invention relies on a controller-transmitter device to deliver ultrasound energy into cardiac tissue in order to directly improve cardiac function and/or to energize one or more implanted receiver-stimulator devices that transduce the ultrasound energy to electrical energy to perform excitatory and/or non-excitatory treatments for heart failure. The acoustic energy can be applied as a single burst or as multiple bursts.
The present technology generally includes devices, systems, and methods for providing electrical stimulation to the left ventricle of a human heart in a patient suffering from Left Bundle Branch Block (LBBB). In particular, the present technology includes an implantable receiver-stimulator and an implantable controller-transmitter for leadless electrical stimulation of the heart. The receiver-stimulator can include one or more sensors capable of detecting the electrical conduction of the heart and the receiver-stimulator can be configured to pace the stimulation of the left ventricle based off the sensed electrical conduction to achieve synchronization of the left and right ventricles.
The present technology is generally directed to medical implants, such as stimulation assemblies for stimulating the septal wall of the heart of a human patent, and associated methods. In some embodiments, a stimulation assembly includes a body, circuitry positioned at least partially within the body, an electrode, and an anchor coupled to the body. The anchor can be secured to the septal wall such that the body is positioned within the left ventricle of the heart and the electrode engages tissue of the septal wall. The circuitry can be configured to receive acoustic energy and to convert the acoustic energy to electrical energy, and the electrode can deliver the electrical energy to the tissue of the septal wall to stimulate the tissue.
The present technology is generally directed to medical implants, such as stimulation assemblies for stimulating the septal wall of the heart of a human patent, and associated methods. In some embodiments, a stimulation assembly includes a body, circuitry positioned at least partially within the body, an electrode, and an anchor coupled to the body. The anchor can be secured to the septal wall such that the body is positioned within the left ventricle of the heart and the electrode engages tissue of the septal wall. The circuitry can be configured to receive acoustic energy and to convert the acoustic energy to electrical energy, and the electrode can deliver the electrical energy to the tissue of the septal wall to stimulate the tissue.
The present technology is generally directed to medical implants, such as stimulation assemblies for stimulating heart tissue. In some embodiments, a stimulation assembly includes a body, circuitry positioned at least partially within the body, an electrode coupled to the body, and a hook mechanism coupled to the body. The stimulation assembly can be implanted at cardiac tissue of a patient such that the electrode electrically contacts the tissue. The circuitry can be configured to receive acoustic energy and convert the acoustic energy to electrical energy, and the electrode can deliver the electrical energy to the tissue to stimulate the tissue. The hook mechanism can be configured to engage the tissue to pull the tissue and the electrode toward and into engagement with one another.
The present technology is generally directed to delivery systems for medical implants, such as electrode assemblies for stimulating heart tissue. In some embodiments, a delivery system for a medical implant includes an elongate sheath having a distal portion and a balloon coupled to the distal portion of the sheath. The delivery system can further include a fluid circuit configured to be in fluid communication with the balloon and having a pressure source and a pressure sensor. The pressure source can move the balloon between an inflated configuration and a deflated configuration, and the pressure sensor can sense a pressure within the balloon. The sensed pressure can be monitored to determine (i) that the balloon is in contact with heart tissue of a heart, (ii), a motion profile of the heart tissue, and/or (iii) blood flow characteristics within the heart.
The present technology is generally directed to delivery systems for medical implants, such as electrode assemblies for stimulating heart tissue. In some embodiments, a delivery system for a medical implant includes an elongate sheath having a distal portion and a balloon coupled to the distal portion of the sheath. The delivery system can further include a fluid circuit configured to be in fluid communication with the balloon and having a pressure source and a pressure sensor. The pressure source can move the balloon between an inflated configuration and a deflated configuration, and the pressure sensor can sense a pressure within the balloon. The sensed pressure can be monitored to determine (i) that the balloon is in contact with heart tissue of a heart, (ii), a motion profile of the heart tissue, and/or (iii) blood flow characteristics within the heart.
A61N 1/05 - Electrodes for implantation or insertion into the body, e.g. heart electrode
A61B 90/00 - Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups , e.g. for luxation treatment or for protecting wound edges
16.
Implantable stimulation assemblies having tissue engagement mechanisms, and associated systems and methods
The present technology is generally directed to medical implants, such as stimulation assemblies for stimulating heart tissue. In some embodiments, a stimulation assembly includes a body, circuitry positioned at least partially within the body, an electrode coupled to the body, and a hook mechanism coupled to the body. The stimulation assembly can be implanted at cardiac tissue of a patient such that the electrode electrically contacts the tissue. The circuitry can be configured to receive acoustic energy and convert the acoustic energy to electrical energy, and the electrode can deliver the electrical energy to the tissue to stimulate the tissue. The hook mechanism can be configured to engage the tissue to pull the tissue and the electrode toward and into engagement with one another.
Cardiac stimulation device, namely, cardiac pacemakers; cardiac resynchronization therapy system comprising a pacing device, catheter, sheath, electrode, battery and transmitter; medical device, namely, a device for synchronizing the contraction of the right and left sides of the heart; medical devices and apparatuses for stimulating the heart that incorporate implantable acoustic controller-transmitters, electrical sensors, and implantable acoustics receivers and stimulators, namely, cardiac pacemakers.
18.
Implantable wireless acoustic stimulators with high energy conversion efficiencies
A controller-transmitter transmits acoustic energy through the body to an implanted acoustic receiver-stimulator. The receiver-stimulator converts the acoustic energy into electrical energy and delivers the electrical energy to tissue using an electrode assembly. The receiver-stimulator limits the output voltage delivered to the tissue to a predetermined maximum output voltage. In the presence of interfering acoustic energy sources output voltages are thereby limited prior to being delivered to the tissue.
A61N 1/375 - Constructional arrangements, e.g. casings
A61N 1/372 - Arrangements in connection with the implantation of stimulators
H02N 2/18 - Electric machines in general using piezoelectric effect, electrostriction or magnetostriction producing electrical output from mechanical input, e.g. generators
H10N 30/03 - Assembling devices that include piezoelectric or electrostrictive parts
H10N 30/30 - Piezoelectric or electrostrictive devices with mechanical input and electrical output, e.g. functioning as generators or sensors
Cardiac stimulation device, namely, cardiac pacemakers; cardiac resynchronization therapy system comprising a pacing device, catheter, sheath, electrode, battery and transmitter; medical device, namely, a device for synchronizing the contraction of the right and left sides of the heart; medical devices and apparatuses for stimulating the heart that incorporate implantable acoustic controller-transmitters, electrical sensors, and implantable acoustics receivers and stimulators, namely, cardiac pacemakers
20.
Pulse delivery device including slew rate detector, and associated systems and methods
The present technology is generally directed to implantable medical device systems configured to provide cardiac resynchronization therapy. In some embodiments, the implantable medical device system comprises a housing, electrodes carried by the housing, a transducer configured to produce input voltage signals in response to ultrasound energy, and a circuit configured to provide, via an electrical pathway, output voltage signals based on the input voltage signals. The circuit comprises a movable switch, and a slew rate detector configured to detect whether a voltage rate of an individual pulse of the input voltage signals exceeds a predetermined threshold voltage rate. The circuit is configured to move the switch to an open position in response to the detected voltage rate exceeding the predetermined threshold voltage rate.
H02M 3/07 - Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using resistors or capacitors, e.g. potential divider using capacitors charged and discharged alternately by semiconductor devices with control electrode
H02N 2/18 - Electric machines in general using piezoelectric effect, electrostriction or magnetostriction producing electrical output from mechanical input, e.g. generators
A61B 8/12 - Diagnosis using ultrasonic, sonic or infrasonic waves in body cavities or body tracts, e.g. by using catheters
21.
Devices, systems, and methods for cardiac resynchronization therapy
The present technology generally includes devices, systems, and methods for providing electrical stimulation to the left ventricle of a human heart in a patient suffering from Left Bundle Branch Block (LBBB). In particular, the present technology includes an implantable receiver-stimulator and an implantable controller-transmitter for leadless electrical stimulation of the heart. The receiver-stimulator can include one or more sensors capable of detecting the electrical conduction of the heart and the receiver-stimulator can be configured to pace the stimulation of the left ventricle based off the sensed electrical conduction to achieve synchronization of the left and right ventricles.
Method and systems for optimizing acoustic energy transmission in implantable devices are disclosed. Transducer elements transmit acoustic locator signals towards a receiver assembly, and the receiver responds with a location signal. The location signal can reveal information related to the location of the receiver and the efficiency of the transmitted acoustic beam received by the receiver. This information enables the transmitter to target the receiver and optimize the acoustic energy transfer between the transmitter and the receiver. The energy can be used for therapeutic purposes, for example, stimulating tissue or for diagnostic purposes.
Systems, devices, and methods for tracking and determining the motion of a cardiac implant is disclosed. The motion of the implant is determined by transmitting acoustic energy to a tissue location using an acoustic controller-transmitter comprising an array of acoustic transducers; wherein the implant is configured to convert the transmitted acoustic energy to electrical energy; and the tracking is achieved by determining the electrical energy delivered to the tissue throughout one or more cardiac cycles in order to create a motion profile of the cardiac implant.
Cardiac stimulation device, namely, cardiac pacemakers; cardiac resynchronization therapy system comprising a pacing device, sheath, battery and transmitter; medical device, namely, a device for synchronizing the contraction of the right and left sides of the heart; medical devices and apparatuses for stimulating the heart that incorporate implantable acoustic controller-transmitters, electrical sensors, and implantable acoustics receivers and stimulators, namely, cardiac pacemakers.
25.
Methods and systems for heart failure prevention and treatments using ultrasound and leadless implantable devices
The present invention relies on a controller-transmitter device to deliver ultrasound energy into cardiac tissue in order to directly improve cardiac function and/or to energize one or more implanted receiver-stimulator devices that transduce the ultrasound energy to electrical energy to perform excitatory and/or non-excitatory treatments for heart failure. The acoustic energy can be applied as a single burst or as multiple bursts.
Cardiac stimulation device, namely, cardiac pacemakers; cardiac resynchronization therapy system comprising a pacing device, catheter, sheath, electrode, battery and transmitter; medical device, namely, a device for synchronizing the contraction of the right and left sides of the heart; medical devices and apparatuses for stimulating the heart that incorporate implantable acoustic controller-transmitters, electrical sensors, and implantable acoustics receivers and stimulators, namely, cardiac pacemakers
27.
Implantable wireless accoustic stimulators with high energy conversion efficiencies
A controller-transmitter transmits acoustic energy through the body to an implanted acoustic receiver-stimulator. The receiver-stimulator converts the acoustic energy into electrical energy and delivers the electrical energy to tissue using an electrode assembly. The receiver-stimulator limits the output voltage delivered to the tissue to a predetermined maximum output voltage. In the presence of interfering acoustic energy sources output voltages are thereby limited prior to being delivered to the tissue.
Furthermore, the controller-transmitter estimates the output voltage that is delivered to the tissue by the implanted receiver-stimulator. The controller-transmitter measures a query spike voltage resulting from the electrical energy delivered to the tissue by the receiver-stimulator, and computes a ratio of the predetermined maximum output voltage and a maximum query spike voltage. The maximum query spike voltage is computed by detecting a query spike voltage plateau. Based on this ratio, the controller-transmitter uses a measured query spike voltage to estimate the output voltage delivered by the receiver-stimulator to tissue.
A61N 1/375 - Constructional arrangements, e.g. casings
H01L 41/113 - Piezo-electric or electrostrictive elements with mechanical input and electrical output
H02N 2/18 - Electric machines in general using piezoelectric effect, electrostriction or magnetostriction producing electrical output from mechanical input, e.g. generators
Systems, devices, and methods for tracking and determining the motion of a cardiac implant is disclosed. The motion of the implant is determined by transmitting acoustic energy to a tissue location using an acoustic controller-transmitter comprising an array of acoustic transducers; wherein the implant is configured to convert the transmitted acoustic energy to electrical energy; and the tracking is achieved by determining the electrical energy delivered to the tissue throughout one or more cardiac cycles in order to create a motion profile of the cardiac implant.
Method and systems for optimizing acoustic energy transmission in implantable devices are disclosed. Transducer elements transmit acoustic locator signals towards a receiver assembly, and the receiver responds with a location signal. The location signal can reveal information related to the location of the receiver and the efficiency of the transmitted acoustic beam received by the receiver. This information enables the transmitter to target the receiver and optimize the acoustic energy transfer between the transmitter and the receiver. The energy can be used for therapeutic purposes, for example, stimulating tissue or for diagnostic purposes.
Receiver-stimulator with folded or rolled up assembly of piezoelectric components, causing the receiver-stimulator to operate with a high degree of isotropy are disclosed. The receiver-stimulator comprises piezoelectric components, rectifier circuitry, and at least two stimulation electrodes. Isotropy allows the receiver-stimulator to be implanted with less concern regarding the orientation relative the transmitted acoustic field from an acoustic energy source.
A61N 1/375 - Constructional arrangements, e.g. casings
A61N 1/372 - Arrangements in connection with the implantation of stimulators
H01L 41/113 - Piezo-electric or electrostrictive elements with mechanical input and electrical output
H02N 2/18 - Electric machines in general using piezoelectric effect, electrostriction or magnetostriction producing electrical output from mechanical input, e.g. generators
Delivery of an implantable wireless receiver-stimulator (R-S) into the heart using delivery catheter is described. R-S comprises a cathode and an anode and wirelessly receives and converts energy, such as acoustic ultrasound energy, to electrical energy to stimulate the heart. Conductive wires routed through the delivery system temporarily connect R-S electrodes to external monitor and pacing controller. R-S comprises a first temporary electrical connection from the catheter to the cathode, and a second temporary electrical connection from the catheter to the anode. Temporary electrical connections allow external monitoring of heart's electrical activity as sensed by R-S electrodes to determine tissue viability for excitation as well as to assess energy conversion efficiency.
A system for delivering an electrical stimulation pulse to tissue comprises a controller-transmitter and a receiver-stimulator. The controller-transmitter includes circuitry having an energy storage capacitor. The capacitance of the energy storage capacitor is adjusted to improve the efficiency of energy delivered from the receiver-stimulator to tissue by modifying the geometry of an acoustic drive burst from the controller-transmitter.
A system for delivering an electrical stimulation pulse to tissue comprises a controller-transmitter and a receiver-stimulator. The controller-transmitter includes circuitry having an energy storage capacitor. The capacitance of the energy storage capacitor is adjusted to improve the efficiency of energy delivered from the receiver-stimulator to tissue by modifying the geometry of an acoustic drive burst from the controller-transmitter.
Systems and methods are disclosed to stimulate tissue to treat medical conditions involving tissues such as the bone, spine, stomach, nerves, brain and the cochlea. The disclosed invention uses electrical stimulation of the tissue, where vibrational (or acoustic) energy from a source is received by an implanted device and converted to electrical energy and the converted electrical energy is used by implanted electrodes to stimulate the pre-determined tissue sites. The vibrational energy is generated by a controller-transmitter, which could be either implanted or located externally. The vibrational energy is received by a receiver-stimulator, which could be located at or close to the stimulation site.
Receiver-stimulator with folded or rolled up assembly of piezoelectric components, causing the receiver-stimulator to operate with a high degree of isotropy are disclosed. The receiver-stimulator comprises piezoelectric components, rectifier circuitry, and at least two stimulation electrodes. Isotropy allows the receiver-stimulator to be implanted with less concern regarding the orientation relative the transmitted acoustic field from an acoustic energy source.
A61N 1/375 - Constructional arrangements, e.g. casings
H01L 41/113 - Piezo-electric or electrostrictive elements with mechanical input and electrical output
H02N 2/18 - Electric machines in general using piezoelectric effect, electrostriction or magnetostriction producing electrical output from mechanical input, e.g. generators
The present invention relies on a controller-transmitter device to deliver ultrasound energy into cardiac tissue in order to directly improve cardiac function and/or to energize one or more implanted receiver-stimulator devices that transduce the ultrasound energy to electrical energy to perform excitatory and/or non-excitatory treatments for heart failure. The acoustic energy can be applied as a single burst or as multiple bursts.
Delivery of an implantable wireless receiver-stimulator (R-S) into the heart using delivery catheter is described. R-S comprises a cathode and an anode and wirelessly receives and converts energy, such as acoustic ultrasound energy, to electrical energy to stimulate the heart. Conductive wires routed through the delivery system temporarily connect R-S electrodes to external monitor and pacing controller. R-S comprises a first temporary electrical connection from the catheter to the cathode, and a second temporary electrical connection from the catheter to the anode. Temporary electrical connections allow external monitoring of heart's electrical activity as sensed by R-S electrodes to determine tissue viability for excitation as well as to assess energy conversion efficiency.
A wireless cardiac stimulation device is disclosed comprising a controller-transmitter, a receiver, and a stimulating electrode, wherein the stimulating electrode and the receiver are separately implantable at cardiac tissue locations of the heart and are connected by a local lead. Having separately implantable receiver and stimulating electrodes improves the efficiency of ultrasound mediated wireless stimulation by allowing the receiver to be placed optimally for reception efficiency, thereby resulting in longer battery life, and by allowing the stimulating electrode to be placed optimally for stimulus delivery. Another advantage is a reduced risk of embolization, since the receiver and stimulating electrode ensemble is attached at two locations of the heart wall, with the connecting local leads serving as a safety tether should either the receiver or the stimulating electrode become dislodged.
A61N 1/368 - Heart stimulators controlled by a physiological parameter, e.g. by heart potential comprising more than one electrode co-operating with different heart regions
A61N 1/375 - Constructional arrangements, e.g. casings
40.
Method of manufacturing implantable wireless acoustic stimulators with high energy conversion efficiencies
Receiver-stimulator with folded or rolled up assembly of piezoelectric components, causing the receiver-stimulator to operate with a high degree of isotropy are disclosed. The receiver-stimulator comprises piezoelectric components, rectifier circuitry, and at least two stimulation electrodes. Isotropy allows the receiver-stimulator to be implanted with less concern regarding the orientation relative the transmitted acoustic field from an acoustic energy source.
A system for delivering an electrical stimulation pulse to tissue comprises a controller-transmitter and a receiver-stimulator. The controller-transmitter includes circuitry having an energy storage capacitor. The capacitance of the energy storage capacitor is adjusted to improve the efficiency of energy delivered from the receiver-stimulator to tissue by modifying the geometry of an acoustic drive burst from the controller-transmitter.
Method and systems for optimizing acoustic energy transmission in implantable devices are disclosed. Transducer elements transmit acoustic locator signals towards a receiver assembly, and the receiver responds with a location signal. The location signal can reveal information related to the location of the receiver and the efficiency of the transmitted acoustic beam received by the receiver. This information enables the transmitter to target the receiver and optimize the acoustic energy transfer between the transmitter and the receiver. The energy can be used for therapeutic purposes, for example, stimulating tissue or for diagnostic purposes.
A system for delivering an electrical stimulation pulse to tissue comprises a controller-transmitter and a receiver-stimulator. The controller-transmitter includes circuitry having an energy storage capacitor. The capacitance of the energy storage capacitor is adjusted to improve the efficiency of energy delivered from the receiver-stimulator to tissue by modifying the geometry of an acoustic drive burst from the controller-transmitter.
Method and systems for determining the location or identify of implantable devices are disclosed. An implantable device generates an electrical output and then modifies the output at a pre-configured interval for a pre-configured period. A sensor detects the modified output and locates or identifies the implantable device based on the modified output.
Receiver-stimulator with folded or rolled up assembly of piezoelectric components, causing the receiver-stimulator to operate with a high degree of isotropy are disclosed. The receiver-stimulator comprises piezoelectric components, rectifier circuitry, and at least two stimulation electrodes. Isotropy allows the receiver-stimulator to be implanted with less concern regarding the orientation relative the transmitted acoustic field from an acoustic energy source.
A61N 1/375 - Constructional arrangements, e.g. casings
H01L 41/113 - Piezo-electric or electrostrictive elements with mechanical input and electrical output
H02N 2/18 - Electric machines in general using piezoelectric effect, electrostriction or magnetostriction producing electrical output from mechanical input, e.g. generators
H01L 41/25 - Assembling devices that include piezo-electric or electrostrictive parts
Systems including an implantable receiver-stimulator and an implantable controller-transmitter are used for leadless electrical stimulation of body tissues. Cardiac pacing and arrhythmia control is accomplished with one or more implantable receiver-stimulators and an external or implantable controller-transmitter. Systems are implanted by testing external or implantable devices at different tissue sites, observing physiologic and device responses, and selecting sites with preferred performance for implanting the systems. In these systems, a controller-transmitter is activated at a remote tissue location to transmit/deliver acoustic energy through the body to a receiver-stimulator at a target tissue location. The receiver-stimulator converts the acoustic energy to electrical energy for electrical stimulation of the body tissue. The tissue locations(s) can be optimized by moving either or both of the controller-transmitter and the receiver-stimulator to determine the best patient and device responses.
A61N 1/372 - Arrangements in connection with the implantation of stimulators
A61N 1/375 - Constructional arrangements, e.g. casings
A61N 1/368 - Heart stimulators controlled by a physiological parameter, e.g. by heart potential comprising more than one electrode co-operating with different heart regions
47.
Systems and methods for implantable leadless tissue stimulation
Systems and methods are disclosed to stimulate tissue to treat medical conditions involving tissues such as the bone, spine, stomach, nerves, brain and the cochlea. The disclosed invention uses electrical stimulation of the tissue, where vibrational (or acoustic) energy from a source is received by an implanted device and converted to electrical energy and the converted electrical energy is used by implanted electrodes to stimulate the pre-determined tissue sites. The vibrational energy is generated by a controller-transmitter, which could be either implanted or located externally. The vibrational energy is received by a receiver-stimulator, which could be located at or close to the stimulation site.
A controller-transmitter transmits acoustic energy through the body to an implanted acoustic receiver-stimulator. The receiver-stimulator converts the acoustic energy into electrical energy and delivers the electrical energy to tissue using an electrode assembly. The receiver-stimulator limits the output voltage delivered to the tissue to a predetermined maximum output voltage. In the presence of interfering acoustic energy sources output voltages are thereby limited prior to being delivered to the tissue. Furthermore, the controller-transmitter estimates the output voltage that is delivered to the tissue by the implanted receiver-stimulator. The controller-transmitter measures a query spike voltage resulting from the electrical energy delivered to the tissue by the receiver-stimulator, and computes a ratio of the predetermined maximum output voltage and a maximum query spike voltage. The maximum query spike voltage is computed by detecting a query spike voltage plateau. Based on this ratio, the controller-transmitter uses a measured query spike voltage to estimate the output voltage delivered by the receiver-stimulator to tissue.
Receiver-stimulator with folded or rolled up assembly of piezoelectric components, causing the receiver-stimulator to operate with a high degree of isotropy are disclosed. The receiver-stimulator comprises piezoelectric components, rectifier circuitry, and at least two stimulation electrodes. Isotropy allows the receiver-stimulator to be implanted with less concern regarding the orientation relative the transmitted acoustic field from an acoustic energy source.
Systems and methods are disclosed to enhance bone growth by stimulating bone sites for bone regrowth, fusion, or grafts. The invention uses electrical stimulation of the bone site, where vibrational energy from a source is received by an implanted device and converted to electrical energy and the converted electrical energy is used by implanted electrodes to stimulate the bone site. The vibrational energy is generated by a controller-transmitter, which could be located either externally or implanted. The vibrational energy is received by a receiver-transmitter, which could be incorporated into an orthopedic device, such as pin, cage, plate or prosthetic joint used for bone healing.
Delivery of an implantable wireless receiver-stimulator (R-S) into the heart using delivery catheter is described. R-S comprises a cathode and an anode and wirelessly receives and converts energy, such as acoustic ultrasound energy, to electrical energy to stimulate the heart. Conductive wires routed through the delivery system temporarily connect R-S electrodes to external monitor and pacing controller. R-S comprises a first temporary electrical connection from the catheter to the cathode, and a second temporary electrical connection from the catheter to the anode. Temporary electrical connections allow external monitoring of heart's electrical activity as sensed by R-S electrodes to determine tissue viability for excitation as well as to assess energy conversion efficiency.
A controller-transmitter transmits acoustic energy through the body to an implanted acoustic receiver-stimulator. The receiver-stimulator converts the acoustic energy into electrical energy and delivers the electrical energy to tissue using an electrode assembly. The receiver-stimulator limits the output voltage delivered to the tissue to a predetermined maximum output voltage. In the presence of interfering acoustic energy sources output voltages are thereby limited prior to being delivered to the tissue. Furthermore, the controller-transmitter estimates the output voltage that is delivered to the tissue by the implanted receiver-stimulator. The controller-transmitter measures a query spike voltage resulting from the electrical energy delivered to the tissue by the receiver-stimulator, and computes a ratio of the predetermined maximum output voltage and a maximum query spike voltage. The maximum query spike voltage is computed by detecting a query spike voltage plateau.
Systems and methods are disclosed to stimulate brain tissue to treat medical conditions such as movement disorders, pain and epilepsy. The disclosed invention uses electrical stimulation of the brain tissue, where vibrational energy from a source is received by an implanted device and converted to electrical energy and the converted electrical energy is used by implanted electrodes to stimulate the pre-determined brain site. The vibrational energy is generated by a controller-transmitter, which could be either implanted or located externally. The vibrational energy is received by a receiver-stimulator, which could be located under the skull, within the brain, on the dura, or in the cranial space close to the brain. As a therapeutic treatment, the implantable receiver-stimulator stimulates the brain sites that are effective in altering brain activity.
Systems and methods are disclosed to stimulate spine tissue to treat medical conditions such as pain and spinal injury. The invention uses electrical stimulation of the spine, where vibrational energy from a source is received by an implanted device and converted to electrical energy and the converted electrical energy is used by implanted electrodes to stimulate the pre-determined brain site. The vibrational energy is generated by a controller-transmitter, which could be located either externally or implanted. The vibrational energy is received by a receiver-stimulator, which could be located in the various regions on around the spine. The implantable receiver-stimulator stimulates different locations in the spine region to provide therapeutic benefit.
Systems and methods are disclosed to enable hearing in the deaf by stimulating sites in the cochlea. The invention uses electrical stimulation in the cochlea, where vibrational energy from a source is received by an implanted device and converted to electrical energy and the converted electrical energy is used by implanted electrodes to stimulate the cochlear nerve. The vibrational energy is generated by a controller-transmitter, which could be located either externally or implanted. The vibrational energy is received by a receiver-stimulator, which contains multiple electrodes to stimulate along selected sites in the cochlea.
Systems and methods are disclosed to stimulate nerves to treat medical conditions such as pain, and other conditions, such as, CHF, obesity, incontinence, etc., that could be controlled by the stimulation of the vagal nerves. The invention uses electrical stimulation of the nerve, where vibrational energy from a source is received by an implanted device and converted to electrical energy and the converted electrical energy is used by implanted electrodes to stimulate the pre-determined nerve site. The vibrational energy is generated by a controller-transmitter, which could be implanted or located externally. The vibrational energy is received by a receiver-stimulator, which could be located in the various regions on or around the nerve that needs to be stimulated. The implantable receiver-stimulator stimulates different nerves and regions of a nerve to provide therapeutic benefit.
Systems and methods are disclosed to stimulate gastrointestinal tissue to treat medical conditions such as eating disorders, gastroparesis, and gastric reflux. The invention uses electrical stimulation of the nerve, where vibrational energy from a source is received by an implanted device and converted to electrical energy and the converted electrical energy is used by implanted electrodes to stimulate the pre-determined gastrointestinal tissue site. The vibrational energy is generated by a controller-transmitter, which could be implanted or located externally. The vibrational energy is received by a receiver-stimulator, which could be located in the various regions on or around the gastrointestinal tissue that needs to be stimulated. The implantable receiver-stimulator stimulates different gastrointestinal tissue to provide the desired therapeutic benefit.
The present invention relies on a controller-transmitter device to deliver ultrasound energy into cardiac tissue in order to directly improve cardiac function and/or to energize one or more implanted receiver-stimulator devices that transduce the ultrasound energy to electrical energy to perform excitatory and/or non-excitatory treatments for heart failure. The acoustic energy can be applied as a single burst or as multiple bursts.
A controller-transmitter transmits acoustic energy through the body to an implanted acoustic receiver-stimulator. The receiver-stimulator converts the acoustic energy into electrical energy and delivers the electrical energy to tissue using an electrode assembly. The receiver-stimulator limits the output voltage delivered to the tissue to a predetermined maximum output voltage. In the presence of interfering acoustic energy sources output voltages are thereby limited prior to being delivered to the tissue.
Furthermore, the controller-transmitter estimates the output voltage that is delivered to the tissue by the implanted receiver-stimulator. The controller-transmitter measures a query spike voltage resulting from the electrical energy delivered to the tissue by the receiver-stimulator, and computes a ratio of the predetermined maximum output voltage and a maximum query spike voltage. The maximum query spike voltage is computed by detecting a query spike voltage plateau. Based on this ratio, the controller-transmitter uses a measured query spike voltage to estimate the output voltage delivered by the receiver-stimulator to tissue.
Systems including an implantable receiver-stimulator and an implantable controller-transmitter are used for leadless electrical stimulation of body tissues. Cardiac pacing and arrhythmia control is accomplished with one or more implantable receiver-stimulators and an external or implantable controller-transmitter. Systems are implanted by testing external or implantable devices at different tissue sites, observing physiologic and device responses, and selecting sites with preferred performance for implanting the systems. In these systems, a controller-transmitter is activated at a remote tissue location to transmit/deliver acoustic energy through the body to a receiver-stimulator at a target tissue location. The receiver-stimulator converts the acoustic energy to electrical energy for electrical stimulation of the body tissue. The tissue locations(s) can be optimized by moving either or both of the controller-transmitter and the receiver-stimulator to determine the best patient and device responses.
Systems including an implantable receiver-stimulator and an implantable controller-transmitter are used for leadless electrical stimulation of body tissues. Cardiac pacing and arrhythmia control is accomplished with one or more implantable receiver-stimulators and an external or implantable controller-transmitter. Systems are implanted by testing external or implantable devices at different tissue sites, observing physiologic and device responses, and selecting sites with preferred performance for implanting the systems. In these systems, a controller-transmitter is activated at a remote tissue location to transmit/deliver acoustic energy through the body to a receiver-stimulator at a target tissue location. The receiver-stimulator converts the acoustic energy to electrical energy for electrical stimulation of the body tissue. The tissue locations(s) can be optimized by moving either or both of the controller-transmitter and the receiver-stimulator to determine the best patient and device responses.
Receiver-stimulators comprise a nearly isotropic transducer assembly, demodulator circuitry, and at least two tissue contacting electrodes. Use of near isotropic transducers allows the devices to be implanted with less concern regarding the orientation relative to an acoustic energy source. Transducers or transducer elements having relatively small sizes, typically less than ½ the wavelength of the acoustic source, enhance isotropy. The use of single crystal piezoelectric materials enhance sensitivity.
Receiver-stimulators comprise a nearly isotropic transducer assembly, demodulator circuitry, and at least two tissue contacting electrodes. Use of near isotropic transducers allows the devices to be implanted with less concern regarding the orientation relative to an acoustic energy source. Transducers or transducer elements having relatively small sizes, typically less than ½ the wavelength of the acoustic source, enhance isotropy. The use of single crystal piezoelectric materials enhance sensitivity.
A wireless cardiac stimulation device comprising an implantable transmitter module housing a transmitter and a separately implantable battery module housing a battery for powering the transmitter and other device electronics via a subcutaneously routable electrical cable connecting the module is disclosed. The transmitter module contains a transmitter enclosure which comprises one or more ultrasound transducers. Having separate transmitter and battery modules allows implantation of the transmitter module closer to the target receiver implanted in tissue. A discrete battery module also enables easy replacement of the battery without disturbing the transmitter, which is highly desirable.
Delivery of an implantable wireless receiver-stimulator (R-S) into the heart using delivery catheter is described. R-S comprises a cathode and an anode and wirelessly receives and converts energy, such as acoustic ultrasound energy, to electrical energy to stimulate the heart. Conductive wires routed through the delivery system temporarily connect R-S electrodes to external monitor and pacing controller. R-S comprises a first temporary electrical connection from the catheter to the cathode, and a second temporary electrical connection from the catheter to the anode. Temporary electrical connections allow external monitoring of heart's electrical activity as sensed by R-S electrodes to determine tissue viability for excitation as well as to assess energy conversion efficiency.
Receiver-stimulator with folded or rolled up assembly of piezoelectric components, causing the receiver-stimulator to operate with a high degree of isotropy are disclosed. The receiver-stimulator comprises piezoelectric components, rectifier circuitry, and at least two stimulation electrodes. Isotropy allows the receiver-stimulator to be implanted with less concern regarding the orientation relative the transmitted acoustic field from an acoustic energy source.
A wireless cardiac stimulation device comprising an implantable transmitter module housing a transmitter and a separately implantable battery module housing a battery for powering the transmitter and other device electronics via a subcutaneously routable electrical cable connecting the module is disclosed. The transmitter module contains a transmitter enclosure which comprises one or more ultrasound transducers. Having separate transmitter and battery modules allows implantation of the transmitter module closer to the target receiver implanted in tissue. A discrete battery module also enables easy replacement of the battery without disturbing the transmitter, which is highly desirable.
Methods and systems for minimizing energy utilization for tissue stimulation using implantable microstimulators are disclosed. Microstimulators of the present invention are designed to minimize the formation of fibrotic tissue, which results in increased energy consumption during tissue stimulation. Furthermore, by using microstimulators in combination with electrodes with small surface areas that are lmm2 or less, tissue can be stimulated using lower energies compared to lead based stimulators with traditional electrode sizes. Small electrode surface areas achieve high current densities and this combined with the small fibrotic cap thickness improves energy utilization in implanted tissue microstimulators. In a preferred embodiment, the microstimulator converts acoustic energy that is received from an acoustic transmitter into electrical energy and the electrical signals are used to stimulate the tissue using optimized energy utilization.
Method and systems for optimizing acoustic energy transmission in implantable devices are disclosed. Transducer elements transmit acoustic locator signals towards a receiver assembly, and the receiver responds with a location signal. The location signal can reveal information related to the location of the receiver and the efficiency of the transmitted acoustic beam received by the receiver. This information enables the transmitter to target the receiver and optimize the acoustic energy transfer between the transmitter and the receiver. The energy can be used for therapeutic purposes, for example, stimulating tissue or for diagnostic purposes.
A61H 1/00 - Apparatus for passive exercising; Vibrating apparatus; Chiropractic devices, e.g. body impacting devices, external devices for briefly extending or aligning unbroken bones
70.
Optimizing energy transmission in a leadless tissue stimulation system
Method and systems for optimizing acoustic energy transmission in implantable devices are disclosed. Transducer elements transmit acoustic locator signals towards a receiver assembly, and the receiver responds with a location signal. The location signal can reveal information related to the location of the receiver and the efficiency of the transmitted acoustic beam received by the receiver. This information enables the transmitter to target the receiver and optimize the acoustic energy transfer between the transmitter and the receiver. The energy can be used for therapeutic purposes, for example, stimulating tissue or for diagnostic purposes.
Systems including an implantable receiver-stimulator and an external controller-transmitter system are used for leadless acute stimulation of the heart, particularly after heart surgery. Cardiac pacing and arrhythmia control is accomplished with one or more implantable receiver-stimulators and an external system that alternatively includes the use of an external pacemaker. Receiver-stimulators are implanted in the heart during surgery or during an acute interventional procedure and then a triggered for stimulation by using the external system. In one embodiment of these systems, a controller-transmitter is activated by an external pacemaker to time the delivery of acoustic energy transmission through the body to a receiver-stimulator at a target tissue location. The receiver-stimulator converts the acoustic energy to electrical energy for electrical stimulation of the heart tissue.
An acoustic transmitter (10) produces a pulsed ultrasound waveform which is transmitted through body tissues to an implanted receiver- stimulator device (5, 23) The waveform has an acoustic amplitude, pulse width, and pulse repetition period, which corresponds to a pacing pulse electrical amplitude, pacing pulse width, and pacing cycle length, respectively The receiver-stimulator device intercepts at least a portion of the transmitted acoustic energy and coverts that acoustic energy into electrical energy using pieEoelectric or other devices This electrical energy is applied to circuitry, which produces a desired stimulating pulse waveform, which is then applied to tissue-contacting electrodes.
Systems and methods are disclosed to stimulate tissue to treat medical conditions involving tissues such as the bone, spine, stomach, nerves, brain and the cochlea The disclosed invention uses electrical stimulation of the tissue, where vibrational (or acoustic) energy from a source (10) is received by an implanted device (20) and converted to electrical energy and the converted electrical energy is used by implanted electrodes (220) to stimulate the pre-determined tissue sites The vibrational energy is generated by a controller- transmitter (160), which could be either implanted or located externally The vibrational energy is received by a receiver-stimulator (200), which could be located at or close to the stimulation site.
An acoustic transmitter produces a pulsed ultrasound waveform which is transmitted through body tissues to an implanted receiver-stimulator device. The waveform has an acoustic amplitude, pulse width, and pulse repetition period, which corresponds to a pacing pulse electrical amplitude, pacing pulse width, and pacing cycle length, respectively. The receiver-stimulator device intercepts at least a portion of the transmitted acoustic energy and coverts that acoustic energy into electrical energy using piezoelectric or other devices. This electrical energy is applied to circuitry, which produces a desired stimulating pulse waveform, which is then applied to tissue-contacting electrodes.
Systems and methods are disclosed to enhance bone growth by stimulating bone sites for bone regrowth, fusion, or grafts. The invention uses electrical stimulation of the bone site, where vibrational energy from a source is received by an implanted device and converted to electrical energy and the converted electrical energy is used by implanted electrodes to stimulate the bone site. The vibrational energy is generated by a controller-transmitter, which could be located either externally or implanted. The vibrational energy is received by a receiver-transmitter, which could be incorporated into an orthopedic device, such as pin, cage, plate or prosthetic joint used for bone healing.
Systems and methods are disclosed to stimulate spine tissue to treat medical conditions such as pain and spinal injury. The invention uses electrical stimulation of the spine, where vibrational energy from a source is received by an implanted device and converted to electrical energy and the converted electrical energy is used by implanted electrodes to stimulate the pre-determined brain site. The vibrational energy is generated by a controller-transmitter, which could be located either externally or implanted. The vibrational energy is received by a receiver-stimulator, which could be located in the various regions on around the spine. The implantable receiver-stimulator stimulates different locations in the spine region to provide therapeutic benefit.
Systems and methods are disclosed to stimulate nerves to treat medical conditions such as pain, and other conditions, such as, CHF, obesity, incontinence, etc., that could be controlled by the stimulation of the vagal nerves. The invention uses electrical stimulation of the nerve, where vibrational energy from a source is received by an implanted device and converted to electrical energy and the converted electrical energy is used by implanted electrodes to stimulate the pre-determined nerve site. The vibrational energy is generated by a controller-transmitter, which could be implanted or located externally. The vibrational energy is received by a receiver-stimulator, which could be located in the various regions on or around the nerve that needs to be stimulated. The implantable receiver-stimulator stimulates different nerves and regions of a nerve to provide therapeutic benefit.
Systems and methods are disclosed to stimulate gastrointestinal tissue to treat medical conditions such as eating disorders, gastroparesis, and gastric reflux. The invention uses electrical stimulation of the nerve, where vibrational energy from a source is received by an implanted device and converted to electrical energy and the converted electrical energy is used by implanted electrodes to stimulate the pre-determined gastrointestinal tissue site. The vibrational energy is generated by a controller-transmitter, which could be implanted or located externally. The vibrational energy is received by a receiver-stimulator, which could be located in the various regions on or around the gastrointestinal tissue that needs to be stimulated. The implantable receiver-stimulator stimulates different gastrointestinal tissue to provide the desired therapeutic benefit.
Systems and methods are disclosed to stimulate brain tissue to treat medical conditions such as movement disorders, pain and epilepsy. The disclosed invention uses electrical stimulation of the brain tissue, where vibrational energy from a source is received by an implanted device and converted to electrical energy and the converted electrical energy is used by implanted electrodes to stimulate the pre-determined brain site. The vibrational energy is generated by a controller-transmitter, which could be either implanted or located externally. The vibrational energy is received by a receiver-stimulator, which could be located under the skull, within the brain, on the dura, or in the cranial space close to the brain. As a therapeutic treatment, the implantable receiver-stimulator stimulates the brain sites that are effective in altering brain activity.
Systems and methods are disclosed to enable hearing in the deaf by stimulating sites in the cochlea. The invention uses electrical stimulation in the cochlea, where vibrational energy from a source is received by an implanted device and converted to electrical energy and the converted electrical energy is used by implanted electrodes to stimulate the cochlear nerve. The vibrational energy is generated by a controller-transmitter, which could be located either externally or implanted. The vibrational energy is received by a receiver-stimulator, which contains multiple electrodes to stimulate along selected sites in the cochlea.
Methods and apparatus for cardiac pacing, cardioversion and defibrillation rely on delivering ultrasonic or other vibrational energy in combination with electrical energy to the heart, usually after the onset of an arrhythmia. A vibrational transducer and suitable electrical contacts may be combined in a single housing or distributed among various housings, and will usually be implantable so that the vibrational transducer can be directed at a target portion of the heart. Alternatively, external systems comprising the vibrational transducer and electrical contacts are also described.
Systems including an implantable receiver-stimulator and an external controller-transmitter system are used for leadless acute stimulation of the heart, particularly after heart surgery. Cardiac pacing and arrhythmia control is accomplished with one or more implantable receiver-stimulators and an external system that alternatively includes the use of an external pacemaker. Receiver-stimulators are implanted in the heart during surgery or during an acute interventional procedure and then a triggered for stimulation by using the external system. In one embodiment of these systems, a controller-transmitter is activated by an external pacemaker to time the delivery of acoustic energy transmission through the body to a receiver-stimulator at a target tissue location. The receiver-stimulator converts the acoustic energy to electrical energy for electrical stimulation of the heart tissue.
A61N 1/368 - Heart stimulators controlled by a physiological parameter, e.g. by heart potential comprising more than one electrode co-operating with different heart regions
83.
METHODS AND APPARATUS FOR DETERMINING CARDIAC STIMULATION SITES USING HEMODYNAMIC DATA
Methods and apparatus for determining an endocardial implantation site for implanting an electrode, such as a leadless stimulation electrode. An embodiment of one method in accordance with the invention includes delivering sufficient electrical energy for initiation of cardiac activation to a plurality of different test locations at the heart of a patient, and determining hemodynamic responses in reaction to that the stimulus delivered to the different test locations. This method further includes identifying an implantation site for implanting the electrode by selecting at least one of the test locations corresponding to a favorable hemodynamic response.
Methods and apparatus for determining an endocardial implantation site for implanting an electrode, such as a leadless stimulation electrode. An embodiment of one method in accordance with the invention includes delivering sufficient electrical energy for initiation of cardiac activation to a plurality of different test locations at the heart of a patient, and determining hemodynamic responses in reaction to that the stimulus delivered to the different test locations. This method further includes identifying an implantation site for implanting the electrode by selecting at least one of the test locations corresponding to a favorable hemodynamic response.
The present invention relies on a controller-transmitter device to deliver ultrasound energy into cardiac tissue in order to directly improve cardiac function and/or to energize one or more implanted receiver-stimulator devices that transduce the ultrasound energy to electrical energy to perform excitatory and/or non-excitatory treatments for heart failure. The acoustic energy can be applied as a single burst or as multiple bursts.
The present invention relies on a controller-transmitter device to deliver ultrasound energy into cardiac tissue in order to directly improve cardiac function and/or to energize one or more implanted receiver-stimulator devices that transduce the ultrasound energy to electrical energy to perform excitatory and/or non-excitatory treatments for heart failure. The acoustic energy can be applied as a single burst or as multiple bursts.
A system for delivering an electrical stimulation pulse to tissue comprises a controller-transmitter and a receiver-stimulator. The controller-transmitter includes circuitry having an energy storage capacitor. The capacitance of the energy storage capacitor is adjusted to improve the efficiency of energy delivered from the receiver-stimulator to tissue by modifying the geometry of an acoustic drive burst from the controller-transmitter.
A system for delivering an electrical stimulation pulse to tissue comprises a controller-transmitter and a receiver-stimulator. The controller-transmitter includes circuitry having an energy storage capacitor. The capacitance of the energy storage capacitor is adjusted to improve the efficiency of energy delivered from the receiver-stimulator to tissue by modifying the geometry of an acoustic drive burst from the controller-transmitter.
Systems including an implantable receiver-stimulator and an implantable controller-transmitter are used for leadless electrical stimulation of body tissues. Cardiac pacing and arrhythmia control is accomplished with one or more implantable receiver-stimulators and an external or implantable controller-transmitter. Systems are implanted by testing external or implantable devices at different tissue sites, observing physiologic and device responses, and selecting sites with preferred performance for implanting the systems. In these systems, a controller-transmitter is activated at a remote tissue location to transmit/deliver acoustic energy through the body to a receiver-stimulator at a target tissue location. The receiver-stimulator converts the acoustic energy to electrical energy for electrical stimulation of the body tissue. The tissue locations(s) can be optimized by moving either or both of the controller-transmitter and the receiver-stimulator to determine the best patient and device responses.
Receiver-stimulators comprise a nearly isotropic transducer assembly, demodulator circuitry, and at least two tissue contacting electrodes. Use of near isotropic transducers allows the devices to be implanted with less concern regarding the orientation relative to an acoustic energy source. Transducers or transducer elements having relatively small sizes, typically less than ½ the wavelength of the acoustic source, enhance isotropy. The use of single crystal piezoelectric materials enhance sensitivity.
Methods and apparatus for cardiac pacing, cardioversion and defibrillation rely on delivering ultrasonic or other vibrational energy in combination with electrical energy to the heart, usually after the onset of an arrhythmia. A vibrational transducer and suitable electrical contacts may be combined in a single housing or distributed among various housings, and will usually be implantable so that the vibrational transducer can be directed at a target portion of the heart. Alternatively, external systems comprising the vibrational transducer and electrical contacts are also described.
